Molding press



Feb. 6, 1945. P. E. FLOWERS 2,368,756

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PAUL EF'Lowms im t Feb. 6, 1945. P. E. FLOWERS 2,368,756

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PAUL F. FLOWERS,

ATTORNEY:

Feb. 6, 1945. P. E. FLOWER-s 2,368,756

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MOLDING PRESS Filed March 2l, 1941 12 Sheets-Sheet 6 Feb. 6,1945. P. E. ,FLOWERSRr 2,368,756

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Feb. 6, 1945. 'l P. E. FLOWERS 2,368,756

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P. E. FLOWERS MOLDING PRESS 12 Sheets-Sheet ll Filed March 2l, 194l .Jn/um PAUL E. FLOWERS,

MOLDING PRESS Filed March 21, 1941 12 Sheets-Sheet 12 ENERGIZATIUN PERIOD PAUL E', FLOWERS, MM

aanvang.:

IEEE'- Patented Feb. y6, 1945 MOLDING PRESS Paul E. Flowers, Mount Gilead, Ohio, assigner to The Hydraulic Development Corporation, Inc., Wilmington, Del., a corporation of Dela- Ware Application March 21, 1941, Serial No. 384,520

13 Claims.

This invention relates to hydraulic machinery, and in particular to hydraulic molding presses.

One object of the invention consists in the provision of a hydraulic molding press, in which mechanical means controls the molding plunger automatically so as to cause the same to carry out different strokes during one and the same working cycle of the press.

Another object is to provide a hydraulic molding press, in which mechanical controlling means is responsive to the travel of the press plunger for causing the latter rst to carry out a molding stroke and thereafter an ejecting stroke.

It is another object to provide a molding press of the type set forth in the preceding paragraph, in which the molding plunger carries out a retraction stroke immediately preceding the ejecting stroke, and in which the said retraction stroke Y is shorter than the molding stroke of the plunger.

Another object of the invention consists in the provision of a press with a hydraulically operable press platen, in which a pressure iluid source for supplying pressure to actuate said platen is mechanically controlled by the latter so as to cause the platen to carry out only a partial retraction stroke following the pressing stroke and thereafter to perform an electing stroke and a complete return stroke. l

It is a further object to provide a molding press comprising a die carrier, in which mechanical means is adapted, in response to the travel of the press plunger, selectively to initiate movement of said die carrier into or out of alignment with said press plunger.

A still further object of the invention consists in the provision of a press as mentioned in the ing the mold, while mechanically controlledy Another object of the invention consists in the' provision of a. molding press having a horizontally reciprocabledie carrier, in which iluid operable means for actuating said die carrier is arranged inthe press bed and may be removed therefrom as a unit. Y

A still funther object is to provide a molding press in which the mold is supported by yielding means adapted to be preloaded during the molding operation for retracting the mold to its initial position.

It is a still further object of the invention to provide a molding press in which means is provided for lling the mold with molding material in response to the initiation of a working cycle,

Y and in which said means is automatically made preceding paragraph, in which the operation of hydraulically Voperable means for reciprocating the die carrier is mechanically controlled in response to the movement of the press plunger.

It is another object of the invention to provide a molding press comprising valve means which is controlled by double lever systems, one lever of which eiects the shifting movement of said valve means in response to a predetermined point of travel of the press plunger, while the other lever of said lever systems locks said iirst mentioned lever in its respective position and releases it only in response to a predetermined point of travel of said press plunger.

It is a. further object to provide a molding press which comprises hydraulically operable motor means for effecting an advancing and a retraction stroke of the press plunger, and a. hydraulically operable cylinder-piston-assembly for lifts ineffective in case the material previously iilled into the mold has not been ejected.

Still another object of the invention consists in the provision of a molding press with a measuring device for measuring oiiand dispensing a predetermined charge into the mold, in which selectively one or a plurality of measured charges may be unloaded into the mold before starting the molding operation.

It is another object to provide a molding press with a combined mechanical and electrical control system, which may selectively be operated with or without the electrical part of said control system.

These and other objects and advantages oi' the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

Figure 1 illustrates a front view of the press according to the invention.

Figure 2 is a side view of the press shown in Figure 1.

Figure 3 is a section along the line 3-3 of Figure 1.

Figure 4 is a section along the line 4--4 of Figure 1.

Figure 5 is a section along the line 5 5 of Figure 3 and shows, partly in section, hydraulic t lifting means for the mold and the die carrier for Figure 12 is a view along the line I2-I2 of y Figure a.

Figure 13 is a view along the line I 3--I3 of Figure 11m.

Figure 14 is a simplified wiring diagram for the electric circuit associated with the press ac-I cording to the invention.

Figure 15 is a more elaborate wiring diagram corresponding to the wiring diagram of Figure 14 but omitting the energizing circuit for the driving motor.

Figure 16 shows diagrammatically the filling of the mold prior to the initiation of the molding stroke.

Figure 17 is a view similar to Figure 16 showing the initial phase of the molding stroke.

Figure 18 illustrates the molding plunger just prior to the beginning of the ejecting stroke.

Figure 19 shows the molding plunger at the end of its ejecting stroke. Figure 20 is a diagrammatic illustration of the hydraulic circuit of the press according to the invention.

Figure 21 is a graph illustrating theplaten` travel and the points of operation of the mechanical controlling means during the travel of the platen.

Figure 22 is an energization chart of the various solenoids controlling the diierent operations during the pressing cycle.

General arromgememf The hydraulic press according to the invention is a vertical molding press having a main molding plunger with an upper die and a movable mold with an opening at its bottom portion, which opening is adapted to be closed by a lower die.

The molding plunger with the upper die, and the mold are movable vertically, whereas the lower die is movable horizontally so that the latter may selectively release the opening at the mold bottom portion to allow the main plunger to eject the molded piece fromthe mold after the completion of a molding stroke. v

Mechanical controlling elements are provided for timing the motions of the main molding plunger, the means for horizontally shifting the lower die, and the operation of the mold raising plungers, so that each will accomplish its motion at the proper relative time.

'Ihe mechanical controlling means cooperate with electric means for controlling the supply of pressure iluid for actuation of the molding This electric circuit is also arranged so that the press may be caused to operate selectively in semi-automatic or full automatic manl ner, so that it respectively carries out one single molding cycle and then stops, or performs a i 4 l plurality of subsequent molding cycles.

Means is also provided for causing the press to accomplish alternate molding and ejection strokes, wherein the moldingv plunger is mechanically controlled so that the ejection stroke thereof is shorter than the molding stroke.

Furthermore, the press according to the invention comprises simplified means in the form of tapered connecting pins for connecting the upper and lower dies to the molding plunger and die carrier respectively, which means materially facilitate the exchange of the dies without having to remove any other parts from the press.

According to a further feature of the invention, a hydraulically operable cylinder-piston-assembly for shifting the lowerdie is arranged within the press bed so that it can be removed therefrom as a unit.

STRUCTURAL ARRANGEMENT General arrangement Referring now to the drawings in detail, the

, press `comprises a press head I0 and a press bed II interconnected with each other by strain rods I2. a press ram I 3 adapted to be actuatedv by pressure fluid supplied by a variable delivery pump I4, which latter is carried by a support I 5 connected to the press head I0.

The variable delivery pump comprises a shiftable flow control member, the position of which,

relative to a central pumping member, determines the delivery of the pump. Pumps of this type are well known in the art and for a more detailed description thereof reference may be had to Patent 2,159,553 to Ernst.

, The .press head also carries a iluid reservoir or surge tank I6. Operatively connected to the p ress ram I3 is a press platen I1 guided on guiding surfaces I8 and supporting a press plunger I9. The press plunger I9 has connected to the lower end thereof an upper die 2|) (Figures l and 4). The upper die 20 is provided lwith a protruding portion 2I engaging a correspondingly recessed portion 22 in the pressing plunger I9 Threaded into the upper die 20 is a bolt 23 engaging a corresponding bore 24 in the pressing plunger I9 and having a tapered bore 25 through which passes a tapered bolt 26. The adjustment of the tapered bolt 26 is eiected by means of a nut 21 which is held in its respective position by a lock nut 28.

Cooperating with the upper die 20 and the'l pressing plunger I9 is a mold 29 comprising a top portion 30, a lower portion 3l and an intermediate portion 32 interconnecting the upper and lower portions 30 and 3|.

The mold 29 is supported by a ange 33 of a movable mold support 34, which is slidable on the guiding surfaces I8. Relative angular movement between the mold 29 and the movable mold support 34 is prevented by a key 35 engaging the support 34 and the mold 29. The movable mold support 34 has connected thereto two piston rods 36 with pistons 31 which .are reciprocably mounted in cylinders 38 housing a spring 39 continuously urging the pistons 3l and, thereby, the mold 29 to their uppermost position. The

movable mold support 34 is furthermore supported by and connected with two jacks generally designated 40, each of which comprises a fluid cylinder-4| and a piston 42.

The mold 29 has a slightly tapered bore 43 therethrough for receiving the molding material, e. g., salt. The slight taper of the bore 43 merely serves the purpose of facilitating the Reciprocably mounted in the press head I0 isl ejection of the molded piece. The lower end of the bore 43 mayv selectively be closed by the lower die 44 which is connected to a die carrier 45 preferably in the salme manner as the upper die 20 to the pressing plunger. v'I'l'ie die carrier 45 is provided with a guiding flange 46 slidably movable in a correspondingly shaped recess 41 of the press bed II (Figure Also connected to the die carrier 45 are two supporting blocks 1294 (Figures 3, 4, 16) which hold the mold 29 lifted and spaced from the die 44 during the ejecting stroke of plunger I9 (Figures 18 and 19).

Detachably connected lto the die carrier 45, for instance by means of screws 48, is an arm 49, the lower end of which is fork shaped and straddles a reduced portion 50 of a die carrier shifting plunger generally designated 5|, one end 52 of which is reciprocably mounted in a cylinder 53, while the other end 54 of the shifting plunger 5| is reciprocably mounted in a cylinder 55. The cylinders 53 and tively connected with conduits 56 and 51. To prevent leakage from the cylinders 53 and 55, the ends thereof facing each other are provided with packing material 58 compressed by glands 59. The other ends of the cylinders 53 and 55 have preferably mounted therein an adjustable abutment, such as a screw 53a and 55a adapted respectively to engage a correspondingly shaped recess 52a and 54a. The cooperation of said recesses and abutment; also serves as cushioning means when the plunger 5| alpproaches'one or the other end position.

Each of the cylinders 53, 55 is held in the press bed II by means 'of a split ring 60 (Figure 7) comprising two segment portions 6| and 62 adapted to be composed to the ring 60. lThe segments 6I and 62 have a flanged ring portion 63 and 64 respectively, adapted to engage an annular recess 65 in the cylinders 53 and 55.

The split ring 60 engages an annular recess 66 in the bed Il and is connected to the latter in any convenient manner, for instance by means of screws 61. Angular displacement between the cylinders 53 and 55 and their respective split rings 60 is prevented by means of locating screws 68. Also passing through the split ring 60 are two bolts 69 (Figure 6) threadedly engaging bolts 10, the ends of which Ipass through a plate 1I connected to the bolts 10 by means of screws 12. As will be clear from the drawings, adjustment of the bolts 6'9 makes it possible to adjust the glands 59 in any desired manner.

To prevent molding material from falling into the space between the cylinders 53 and 55, an apron 13 is connected to the bed II in any convenient manner, and comprises a slot 14 through which passes the arm 49.

A further apron 15, beneath the apron 13, is connected in any convenient manner to the arm 49. The space between the aprons 13 and 15 is iilled with a felt plate 16 connected to the apron 13 and slidable on the apron 15, which latter has attached to its lower side also-a felt plate 11, adapted to slide on the bed plate 18. The apron is so dimensioned that the slot 14 is always closed thereby, irrespective of the Lposition of the arm 49.

The bed plate 18 has also connected therewith, for instance by screws 19, the jacks 40. The piston rods 80 connected with the jack piston 42 have a spherical end engaging a correspondingly shaped wear plate 8| connected in any convenient manner, for instance by bolts 55 are respec- Mechanical control for variable delivery pump According to the present invention the delivery of the variable delivery pump I4 is controlled in response to the travel of the platen I1 in connection with the controlling mechanism shown in Figure 9 in various positions.

This controlling mechanism comprises a reciprocable push rod 84 having adjustably connected to its upper end a collar 85 adapted to engage the arm 86 of a. lever, generally designated 81, which is connected by a link system 88. 89 with the control rod 90 for the ow control of the variable delivery pump I4. The rod 84 has furthermore adjustably connected thereto a collar 9| adapted to be engaged by a flange 92 of the sleeve 93 which is freely movable on the rod 84.

ASlidably mounted on the sleeve 93 is a control member 94, which comprises a yoke member 95 with an annular recess 96 corresponding in diameter to the diameter ofthe ange 92 but somewhat lessin height than the said iiange. The yoke member 95 has pivotally connected thereto two arms 91, the upper ends of which are constantly urged toward each other by means of springs 98.

Furthermore connected to the rod 84 is a sleeve 99 with a flange I 00 adapted to engage the bed II when the rod 84 is in its lowermost position. The yoke member 95 is connected by an.

.in Figure 9s downwardly until its movement is stopped byvengagement of the flange |00 with the |bed II. When now the platen |1 continues its downward movement, the yoke member 95 will also continue its downward movement but since the push rod 84, due tc the engagement of the collar |00 with the bed. II, has been stopped, the inner surfaces of the arms 91 slide over the collar 9| and relative. thereto, thereby spreading, as shown in Figure 915.

Further downward movement of the platen I1 and yoke member 95 causes the arms 91 to pass below the collar 9| so that the springs 98 again move the upper ends of the arms 91 toward each other againstthe push rod 84. When the platen approaches its lowermost point, the sleeve 99 engages the sleeve 93, thereby stopping the latter, but since the sleeve 93 is slidable in the yoke member 95, the latter can still continue its I downward movement. When the platen |1 has reached its lowermost position, the control member of Figure 9 has reached the position shown i'nl Figure 9u. The pump I4 is now reversed so as to cause the platen |1 to move upwardly.

vUpward movement of the platen I1 also causes the yoke member 95 to move upwardly. As a result thereof, the yokeqmember 95, after a predetermined portion of the upward stroke has .which covers that portion of the4 face of the collar 9| so that further upward` movement of the platen and, thereby, of the yoke member 95 lifts the push rod 84. This lifting movement is conveyed through the lever 81 and unks als, a9, to the contra rod su for the Control member of the pump I4, thereby causing the pump to move to neutral or no delivery position. 'Ihe pump then comes to a halt, causing the platen likewise to stop.

Figure 9v shows the position of the yoke member 95 and push rod 84 shortly before the end of the partial retraction stroke, i. e., lwhen the platen |1 has reached the point v in Figure 21.

By means which will later be described, the pump I4 now is moved beyond neutral position to full delivery forward stroke position so that the platen I1 and thereby the yoke member 95 again start to move downwardly. Before the platen approaches 'lts lowermost position, the flange again engages the bed`|| and the sleeve 93 isagain stopped by the sleeve 99. While the platen and thereby the yoke member 95 continue to move downwardly, the inner surfaces of the arms 91 again slide over the collar 9| and spread. However, in contrast to the movement from Figure 9t position to Figure 9u position, the platen comes to a halt before the arms 91 can pass below the collar 9|. The control mechanism then occupies the position shownin Figure 9m.

The pump |4 is now again reversed,`thereby causing the platen to start its retraction stroke. As a result thereof, the yolze member 9,5 is carried upwardly, but since this time the arms 91 are held in spread position until their upper ends have moved above the collar 9|, the arms 91 cannot engage the collar 9|. Consequently, the yoke member 95, together with the arms 91, performs a complete retraction stroke, in contrast to the partial retraction stroke illustrated in Figure 911.

Figure 9e shows the control member shortly before it has reached its uppermost position; The various positions of Figure 9 are indicated in the graph of Figure 21, illustrating `the platen 'travel Hydraulic circuit Referring to Figure 20 diagrammatically illustrating the hydraulic circuit of the press according to the invention, the press cylinder |02 is connected by means of a conduit |03 with one side of the variable delivery pump I4, the other side of which is connected by means of a conduit |04 with push back cylinders |05 having reciprocably mounted therein push back plungers |06 connected with the platen I1 for performing the retraction stroke of the platen. The platen I1 has connected thereto cams |01 and |08, of lwhich the cam |01 is adapted to control a lever mechanism, generally designated |09, which in its turn controls the operation of a three-way valve I I0 of standard design.

The three-way valve ||0 is connected with a conduit III leading to the push back lcylinders |05. A further conduit I|2 connected with the three-Way valve ||0 leads to the cylinders .of the jacks 40, which are interconnected with each other through the conduit I|3. The third conduit ||4 connected with the three-way valve I I0 communicates rwith a conduit |I5 comprising a check valve II6 and leading to the surge tank |'6. 'I'he check valve |I6 allows fiuid to flow from the conduit ||4 into the tank I6 but not in the reverse direction.

To allow manual operation of the three-way valve IIO, the lever mechanism |09 is connected with a member ||1 continuously urged into the position shown in Figure 20v by means of a spring IIB, the lower end of which abuts the member II1, whereas the upper end'of the spring I|8 contacts a stationary abutment ||9. The member ||1 is connected with a rod |20 passing through the spring ||8 and connected with a cable |2| passing over rolers |22 and |23 and connected with an arm |24, one end of which is pivoted at |25, while the other end of the arm |24 is connected with a handle |26. Consequently, pulling the handle |26 downwardly ywill compress the spring ||8 for shifting the lever mech- Aanism |09, thereby actuating the three-way valve I I0. The three-way valve ||0 may-be controlled so as selectively to effect or interrupt hydraulic communication between the push back cylinders I |05 and the jacks 40. o

The cam |08 is adapted to actuate a lever mechanism generally designated |21, which controls a four-way valve |28 of standard design. The four-Way valve |28 is connected with the conduit II5, and is furthermore connected with the conduits 56 and 51. A conduit |29 connected with the four-way valve |28 leads to an auxiliary pump |30, which may be of any desired type, i. e., either a constant delivery pump or a variable delivery pump.

The suction side of the pump |30 is connected with a conduit I3| leading to the tank I6. Mounted in the uid tank I6 is a main cylinder release and pump by-pass valve |32, which is connected by means of a conduit |33 with a conduit |34 leading to the conduit |35, which latter is connected to the conduit |04. The conduit |35 which comprises a check valve |36 leads to the fluid tank I6. The check valve |36 allows fluid to pass from the tank I6 to the conduit |04 but not in the reverse direction.

The conduit |34 comprises a pressure relief valve |31 for releasing excessive pressure in the conduit |34 and is connected through a surge valve |38. The surge valve |38 is preferably of the type disclosed in Patent 2,193,248 to Ernst,

and its main purpose consists in pre-filling the l cylinder |02 when the press ram moves down' tating the initiation of the retractionl stroke by` releasing pressure from the main cylinder |02.

Also connected with the conduit |03 is a conduit |42 leading to a tonnage control valve |43, which may be of any desired design, preferably of the type disclosed in Patent No. 2,224,957 to Ernst.

The lever mechanism |21 is continuously urged into the position shown in Figure 20 by a spring |44. The valve |28 may, if desired, also be operated manually by actuation of the handle |45, which is connected to the cam arm |46 pivotally connected to a support |41fcarried by the four-way valve |28. The operation of the four-way valve |28 controls the supply of pressure fluid to and the exhaust of pressure uid from the die carrier shifting cylinders 53 and 55.

Automatic control of three-way valve Referring to Figure 10, the cam |01 connected to the platen |1 comprises a cam surface |48 which is located in the same plane as the roller |49 rotatably supported by the arm |50 of the lever mechanism ,|I09. The cam |01 furthermore comprises a cam surface |5| which is 1ocated in the same plane as the .roller '|52 rotatably supported by the arm |53 pivotally connected at |54 to the arm |50.

The cam |01 also comprises a surface |55, which is offset with regard to the cam surface |5| so as to allow the roller |52 freely to swing from one position into another position without engaging the surface |55. The arm |53 has a recess |56 which is adapted to receive a pin |51 rigidly connected to the lever arm |50, thereby preventing further clockwise movement of the arm |53. The pivot point |54 of the arm |53 isso arranged that the arm |53 is urged by its own weight to rotate in clockwise direction.

The left end of the arm 53, with regard to Figures l and 12, is continuously engaged by the upper end Vof the stop member |58 carried by the casing of the three-way valve 0. The valve member |59 of the three-way valve .||0 is pivotally connected to the arm |50 by means of a pivot |60. The arm |50 has furthermore pivotally connected thereto a link |6|, which in its turn is pivotally connected to the casing of the three-way valve ||0. The control mechanism of Figure 10 operates as follows: y

supposing that the platen |1, and thereby the cam |01, is moving downwardly, starting from Figure 10a position, the slant surface |62, which in Figure 10a position engages the roller |49, will first move the said roller downwardly, thereby shifting the lever arm |50 in clockwise direction about the pivot |60 so that the valve member |59 will be moved downwardly. When the arm |50 during this shifting movement has reached a predetermined point, the roller |49 engages the cam surface |48 and rolls on this cam surface during the further downward movement of the platen |1.

Since the left upper surface of the lever arm |53 is prevented from moving upwardly by the stop member |58, the shifting movement of the arm |50 causes the roller |52 to move down- Wardly until the pin |51 carried by the arm |50 is fully received by the recess |56 of the lever arm |53. This position is shown in Figure 10b, from which it willA be noted that the roller |52` just engages the Acam surface ||y while thek roller |49 is still in engagement with the cam surface |48. By means later to be described, the movement of the platen is now reversed so that it moves upwardly.

Since now the arm |53, due to the engagement ofvits roller |52 with the cam surface |5|, cannot shift in anti-clockwise direction, it maintains the position shown in Figure b and, due to its connection with the arm |50, also forces the latter to remain in the position shown in Figure 10b. However, since 'the platen |1 moves upwardly, the cam surface |48 disengages the roller |49. 'I'he device is then in the position of Figure 10c. It will be noted thatin this position the arm |53 holds the lever arm |50 in position,

while in the first two phases, Figures 10a and' 10b, thelever arm |50 moved the arm |53 into position. When the platen l1 now continues its upward movement 'and has reachedv a predetermined position, the cam surface |5| finally disengages the roller 52 so that the spring ||8 (Figure Ashifts'both arms |50 and |53 in anticlockwise direction, thereby returning the same to their initial position as shown in Figure 10d.

. Automatic control of'four-way valve` Referring to Figure 11, the cam |08 carried by the platen |1v comprises a cam surface |63 located in the same 'plane as and adapted to cooperate with the roller |64 rotatably supported by the arm |65 which, by means of pivot |66, is pivoted to the lever arm |61 of the lever mechanism |21. The cam |08 furthermore' comf which latter is pivotally'connected to the lever arm |61 likewise by means of the pivot |66.

Each of the armsA |65, |10 has, at oneend thereof, a recess |1|., |12, respectively adapted to engage correspondingly shaped abutments y|13 and '|14 (Figure 13). The. lever arm |61is pivotally connected to alink |15 which in its turn plvotally connected by means of the supporting arm |16 to the casing of the four-way valve|28. The arm 61 is furthermore pivotally connected rby means of the piv'ot |11 to the valve I' plunger |18. The control device of Figure 11 operates in the following manner: A Y. Supposing that the platen `|1, the cam |08 and the lever mechanism |21 are in the position of Figure 11m, and that the platen |1 now starts a downward stroke. Downward movement of the platen also causes a downward movement of the cam- |08 so that the slant cam surface. |19, due to its engagement with the roller |64, shifts mthe latter about the pivot |66 so that it will engage the cam surface |63. Whenthe lever arm |65 has been so moved, it disengages the abutment |13.

Furthermore, movement ,of the cam |08has, at this time, brought the cam surface |68 into *engagement with the roller |69 and, thereby,

' shifted the lever arm |10 likewise about the pivot |66. the position of Figure 11n. Thev pivoty |66 is so arranged with regard to the lever arms |65. and |10 that the said arms, by their own weight, tend to rotate in clockwise direction.

Further downward movement ofthe platen |1 causes the roller` |69 to disengage the cam surface |68 and to return into its horizontal position as shown in Figure 11o, while the-roller When the engages the roller |69 but this shifts the same upwardly and, since the arm |10 engages the abutment |14, it also causes the lever `arm 61 to shift in. clockwise directionA about the pivot 11. This shifting movement of the lever arm= |61 moves the valve plunger |18 to its lowermost position.

'I'he lastmentioned shifting movement of the lever arm |61 carries the arm |65 upwardly vbut while the roller |64 in this uppermost position in Figure 11p does not yet engage the cam surface 63, the roller |69 engages the cam surface |68. vIf now the platen |1 is again moved downwardly, the roller |64 comes into engagement with the cam surface |63, thereby maintaining 'I'he lever mechanism |21 then occupies the lever erm 'ier sc shifted that the ,valve plunger` |18 staysV in its lowermost position. However, the roller |68 disengages the vcam sur- -fface |68A but' still remains in its previous position. The control-system then occupies the position of Figure 11q. Y l

If the platen |1 no w moves upwardly, the cam surface |68 will merely pass beneath the roller l |69 without causing any change in the position of the levers, and when the cam surface |88 has passed beyond the roller |69, the lever-I armsY |65 and |18 are free to return 4to their horizontal position and are so returned by means of the l spring |44. The control mechanism vthen roc- Y cupies the position Aof Figure 111'. v

,The different positions of the control mechanismscf Figures 1o and 11 are aisc-indiceted'm 1 the graph of Figure 21. i

E zecmc circuit Referring ce Figurcis, lao and m designate l the mainrsupply lines. Connected with the main supply'line |88 is a switch arm|82 adapted y 'when in clcse'dvpcsiticn tc contact the terminal V|88 which'is connected to the line |84. Also connected with the line |84 is a normally closed cycle stopswitch i 85 which in its turn is connected with the solenoid |88. 'I'he solenoidV |85 is .f connected by' line '|81 with the normally closed Y l tonnage control switch |88 provided in the tonnage'control valve Hi8 and connected tothe main l Y supply line |81.

the Y energization oi which ascenso Y v into alignment with the mold f bore 48, e.,

is moving from the position of Figure 19 to the position of Figure 16.`

The une vmi 1e'eds tc thesclencid valve 22|,

'which latter `is 'connected by means of line 222 "to a, line 2 28A adapted by closure of the switch .v

blade 224 to be connected with the line. 225 'leading to the main supply line |8|. Connected with the line |81 is aline 221 leadin g to one end of @the ,solenoid'228`iy theother end of which is connectedv to a line 229. The

solenoid 228 controlsthe normally open switch c blades 2,88, 28| andthe normally closed switch blade 232. -pThe switch blade 288A controls the interconnection of lines |84 and 288, the latter of which is connected to the line 234 leading to the terminal `'288. The terminal 235 maybe connected with the terminal 286 connected to the line |84. y

The cycle start switch is the line 238with the'line 238 leading to Vone endiof the solenoid 248. 'Ihe other endof thesolenoid 248 is connected with the switch arm 24| adapted Vselectively to be connected withrthe line 242 orline 248', depending .on whether full automatic or semi-automatic Voperation is desired.

.The operation of the switch blade |88 is coni solenoid |82, one ,end of which is trolled by the n solenoid |9| and the connected with the pump of the'solenoid- |82is'connected to a' line |94 fmainsupplyline |8| byline |93. The othercend I adapted to be connected -with the linev |85 byv switch blade |98. The line |85 b e connected by means of the blade |81 with the line- |98'connected to the line |89 by the normally closed switch blade: 288. 'I'he die limit switch blade |81 is opened when the lower die'44 is in alignmeans of? the is K adaptedy to 'die limit switch ment with the mold bore 48. This opening is' (Figure 16),. 'I'he line |98 efiected'by a camv 228 is adapted to be connected with the line 28| by meansv ofv the switch blade 282. The line 28| comprises a normally closed ramswitch 288 and leads to the line |88. The solenoidI |86 controls,`

in addition to the switch'blade |86, the switch blade 284 adapted to interconnect the line 285 with the line 281 which comprises a normally closed switch 285 and is connected to one end of the solenoid 288, the' other end of which-is connected by line n289 with themainvsupply line lill.` Also connected vwith the main supply line adapted-to means of the switch blade 2li with the line 2|2r leading to a timer-2|8. 'I'heswitch blade 2|'| is controlled by the solenoid 2818which also controls the switch blades 2|4 'and'.2l5. Closure of the switch bladel2|d interconnects the line 2|8 leadingto the line 2|'|.With the line 285.

. Also connected with the -line 2|8 is one Vend Ofa be connected by Y which in its `turn may be solenoid 2|8, the other end of which is conadapted by closure of the c The line 243 is' connected with a line 244 byV the normally clo'sed switch blade 245. The line 244 isconnected to the line 248 which, on one hand, leads to the main supply line |8| and, on the 'other hand, is connected to one end of the solenoid 241. The other end of the solenoid 241 is connected to 'a line 248 adapted; to be connectedwith the line 249 by closure of the switchblade 258. The line 249'which leads to the line |89 is adapted to be connected by means of the switch blade 25|.` with the line 252 which in its turn may be connected with the line 248 by closure of the switch blade 258. The solenoid ;241 controls, in addition to the blades l288, 245 and 258, also the normally closed switch blade 254. The switch blade 254, when closed, con- 'nects the lines 229 and 284.

Also connected with the line" |88 is a line 255 switch blade 255 to be connected with the line 288 leading tothe line 285.

The numeral 251 -designates'a solenoid having one end thereof connected to the line 258. which .leads to line 242,- while the other end of the solenoid vr251 is connected to a line 259 com- The limit switch 268 is normally closed when the e scale is full; while the limitrswitch 25| is normally closed when the lower die 44 is in alignment with the mold boreI 43. The limitswitch 262 is normally closed when the mold is in its lowermost position',l andthe limit switchV 288 normally ,closed when the press plunger |8 is in its uppermost position (Figure'i). f

The line 259 is normally connected with theYV line 264, through thenormally closed switch blade 232. 4The line V264 is connected through the norswitch blade 2|5 withV the line 285l mally closed Y connected to the line 286 byV closure of the switch blade'261 which is controlled `by the solenoid 248. The line 288 is connected to the line 238, which latter may be connected with the line 239 by closure of switch blade 268.

'Ihe solenoid 251 controls the normally open switch blade 269 which is adapted, when closed. to connect the line 218 with the line 21| con- Y designated 22.1 and when in closed position is, adapted to connect assegno@ nected in its turn with oneterniinalofeachy of the switches 299 and 29|.

Connectedvwith` the Vline |99@ is a `line 21-2 vadapted by closure of the switch blade21lto bei connected with line v214 .which leads to the` line |95.

The detailed eIectric'fciIcuit of Figure 1.5V is.

illustrated inasimpliiled diagraminjFigure 14,

in which the corresponding parts are designated.

vwith thesame reference numerals, as inV Figure 15. The dlagramof Figure 14. moreover comprises an additionalcircuitfor the electric motor f vdriving the mainl pump i4. This circuitccxn.-V

prises a starter switch1299, a normally closed stopswitchr29| anda starter-solenoid 292.

` Energfzation chart,A

The enartof Figure zzhes pmttea as ordinates the travel of theplaten |1 and the numbers of the electric control solenoids, whereas the time of travel ofthe platen i1 andthe period of energization of the said solenoids areplotted asl abscissae. e Y.

By consulting this chart, it is; possible immediately to determine the state of energization of all solenoids at any random platen. supposing it is desiredto find out which soleenergized at the position IV of the platen, i. e., at the position when the platen isiustbeginning point of travel of the l will befnotedrth'at thissolenoidis energizedgwhen.` the :platenstarts its iirst downwardfstrokeduring a cycle, i.'e., in position IV, yandlthen .stays ener-V e gized until the platenhas reachedfthe position IV,

i. e.,y is about to start its partialfretraction stroke. The chart shows `furthermore that when. A the` platen has reached position VI andfisabout. start ritsshorteneddownward stroke,: thesolenoid |92 is againL energized and.. stays energizedey until lthe end of; this shortened downwardstroke, in otherwords, untilthe platen has reached p'o- .,sition VII.

Ornimrrou y Semeautomati'c operation The operation of Vthe vpresswill beV best understood in connection withfFigures 2-1` and 22, of

which Figure 21 shows the points vat which, during the travel of the platen; the -various-mechani` cal controlling means are-actuated, while Figure 'f 22 shows `at which points 'of .the travel ofv the,- platen the electric control solenoids are actuated.

Assumingy now that the press isk in the position of Figure 12 with ther automatic controlfor thethree-way valve ||9 vinthe position ofFignoids are energized and which solenoids arel not to start the first downward stroke of a cycle. Fol v lowing the vertical line downwardly from posinon rv,1twi11be noted that this vertical une ents throughfthe horizontal energizationlines pertaining to the solenoids |99,` 249' and 299, which indicates thatY these solenoids-were already' energized prior to the position IV and 4stili remain energized.

The seid veruciu une mrtnem'ieretuehes the beginning of the horizontal energizationlines pertaining to solenoids |92, :|9|, which indicates that at this timel the solenoids |9| and |92 have just been energized.

Since the energizationy lines pertaining lto the solenoids 291', 241 and V2|9 are not crossed no`r touched by the said vertical line, the solenoids 291, 241 and 2|9 are not energiz'edin theposition IV oi.' the platen.

To sumup the situation, a glance at the chart of Figure 22 shows that at the positionIV of the platen |1, the solenoids |96, 249, 299, |92 and |9| are energized, whereas the solenoids 291, 241

and 2| 9 are not energized.

Similarly, examining the situation when the platen is in the position V, i; e., isv about to start its partial retraction stroke, it willbe notedv that thesolenoids' Isl, |92- a'nd-zos have just reached. the end of their energization period, in other words, are now deenergized, whereas the solenoid` 249 is still energized. 'Ihe chart also indicates that at the position V the'solenoid |96`reaches the end of one energization period and immediately thereafter starts a.v new energization period. This last mentionedfeature is due to theV factthat the .tonnage control switch |99 is open fora very short time andclo'ses immediately after the pressure in the press cylinder |92 decreases.

chart also indicates thatat the position of Figure 5 of the platen, the solenoidsr 291, 241 and 2|9 are not energized.

It will also be noted that the chart of Figure 22 indicates at a glance during which period of time of travel of the platen, or between which In addition to the solenoids just mentioned, the

ure 10a and the automatic control for the fourway valve `|28 inv the positionaof Figure 11m; assuming further .that the mechanical control for the variable delivery l"pump |4V is in the posi- -tion of Figure 9a, while the mold V29 and the words, to startthe -press for (Figure 15) and'furthermore closes thev cycle start switch 231'.

This will cause current to ilow from the main supply line |99 through switch: arm |82, cyclestop switch |95,'solenoid |89, line |91, tonnage control switch |99 and main supply line |9|.-

As a result thereof the solenoid |9 6 is energized and causes the switch blades 294 andl99to'move.

to closed position. Closure of the switch blades l294 and |99`atthis cuits.

Current will furthermore flow from-themain time ydoes not close any cirsupply line |99 through the switch arm |92', the

cyclerstopf-switch |99, line .|99,`closedcycle start switch 2 91,rsolenoid 249, line 249,switchebl'ade 245;'lines244` and 249 and themain supplyline |9|`. As a result thereof the solenoid 249 is energizedl and causes the switch blades 299', 291y and 292 to move into closing position. Closure of the switch blade 299 vestablishes a holding circuit for the solenoid249, which holding circuit comprises the main supply line switch |99, line |99, line 239, switch blade 269, solenoid 249, switch arm 24|, line 243, the norlzrally closed switch blade 245, line 244V and` line Closure of the switch'blade 291 establishesa circuit comprising line |99, switch arm |92, cycle stop switch |95, line |99, line 299, line 299, switch blade 291,- line 295, closed switch blade 2|5, line |99, cycle stop 264, closed switch blade 232, line 259, now closed limit switches 263, 262, 26|, 260, solenoid 251, line 258, line 242 and main supply line |8|. This circuit Acauses energization of the solenoid 251 which in its turn trips a scale 215 (Figure 16).

The scale 215 is adapted tov measure a predetermined quantity of molding material, suchV as salt, and has connected thereto a chute 216 which is shiftable about the stationary pivot 211. Tripping of the scale 215 by the solenoid 251 allows vthe salt to ow from the scale through the chute 216 into the mold 29,. When the scale 215 is about empty, the weight 21a, by means |38.' While the ram I3 and the pressing plunger pletely filled, it overcomes the weight 218 so thatl the chute supporting the scale moves from the position of Figure 16 into the position of Figure ofthe'linkage 219 connected tothe chute 216,

shifts the latter into Figure 16 position. This movement causes the switch blade 260 to open switch blade 256.

Closure of the switch blade 256 establishes a.'Y

circuit comprising the main supply line |80, cycle stop switch |85, lines |89 and 255, blade 256, lines 206 and 205, now closed bladeA 204, line 201, solenoid 208, line 209 and main supply line |8|. This circuit energizes the solenoid 208 so that switch blades 2| I and 2|4 move into closing position whereas thevswitchA blade 2|5 opens. Opening of the switchblade 2|,5 breaks the energizing circuit for the scale tripping 'solenoid 251 so that the switch blade 269 opens. Closure of the switch blade 2| 4 establishes a, holding circuit rfor the solenoid 208, which holding circuit comprises the main supply line |80, switch arm |82, cycle stop switch |85, line |89, lines 2'|1 and 2|,6, switch blade 2|4, line 205, now closed blade 204, line 201, solenoid 208, line 209 and main supply line |8|.

Closure of the switch blade 2|| closes the-energizing circuit for the timer 2|3, which circuit comprises main supply line |80, switch arm |82, cycle stop switch |85, line |89, line 2|1, timer 2I3, line 2|2, switch blade 2| line 2|0 and main supply line |8|.

At the end of the time for which the timer 2|3 has been set, the timer switch blade 213 .is closed.

.This establishes a circuit comprising the main supply line |80, switch arm |82, line |89, ram switch 203, the now closed switch blade 202, line |99, switch blade 200, lines |98 and 212, timer switch blade 213, lines 214 and |95, now closed switch blade |96, line |94, solenoid |92, line |93 and main supply line |8|.

Energization of the solenoid |92 causes the switch blade |90 to close, thereby closing the energizing circuit for the Dump solenoid |9|, which circuit comprises the main supply line |80, switch arm |82, cycle stop switch I 85, line |89, switch blade |90, pump solenoid |9|, line |93 and main supply line |8|.V Energization of the pump solenoid |9I actuates, by means of the linkage 88, 89 (Figures 9 and 20), the flow control member of the pump |4 so as to shift the latter to full delivery forward stroke position.

` Pressure iluid is now delivered by the pump I4 through the conduit |03 intoI the upper portion of the press cylinder |02, while fluid is withdrawn from the push back cylinders |05 through the conduit |04 to the suction `side of the Dump I4. The press ram |3 now moves downwardly by gravity and the fluid delivered by the pump I4 through the conduit |03 intothe press cylinder |02 is supplemented by fluid from the fluid tank I6, which fluid passes through the surge valve 17, thereby opening the switch blade 256. Opening of the switch blade 256 deenergizes the solenoid 208, thereby breaking the energizing circuit for the timer 2|3. As a result thereof the timer switch blade 213 opens and the timer is reset.

When the pressing plunger\|9 during its downward movement has reached the position of Figure 11, it has already partially compressed the salt in the mold, which latter, due to the yfriction between the salt and the mold, has likewise been moved downwardly against the thrust of the spring 39, which previously held the mold in its normal upper or idle position. The downward movement of the mold 29 also eXpels uid from the jacks 40 through the conduit II2, the threeup iny the press cylinder |02 and the surge valve When the lplaten I1 has moved from the position a to the position b in Figure 21, the cam |01 of the platen I1 has shifted the three-way valve ||0 from Figure 10a position into Figure 10b position in the'manner previously described under Automatic control of three-way valve. This shifting movement of the three-way valve ||0 breaks the connection between the conduit ||2 and the conduit I|5 and establishes hydraulic connection between the conduit I I2 andthe conduit |I| connected to the push back cylinders |05. The jacks 40 and the push back cylinders |05 then remain interconnected during the present downward stroke of the platen I1. During the same downward stroke, the four-way valve `inrwhich fluid pressure from the pump |30 is `conveyed through conduit |29, four-way valve |28 and 'conduit 51 into the die carrier shifting cylinder 55, while the four-way valve |28 simultaneously interconnects the conduit 56 connected `with the die carrier shifting cylinder 53 with the exhaust line ||5. i

During this downward stroke of the platen |1 which is illustrated by the portions s-t-a-b-mn-u in the graph of Figure 21, the push or control rod 84 moves from Figure 9s .position into Figure 9u position, in the manner previously described under Mechanical control for variable delivery pump.

When the salt has been compressed to a desired extent, a predetermined pressure has built up in the press cylinder |02, which pressure is conveyed through the conduits |03 and |42 to thetonnage control valve |43 so that the tonnage control switch |88 opens. Opening of the tonnage control switch |88 breaks the energizing circuit for the solenoid |86 so that the switch blades 204 and |96 open.

Opening of the blade |96 breaks the energizing A 

